The need to reduce automotive fuel consumption and emissions is well known. Therefore, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles because they are selectively driven by battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to drive the vehicle.
High voltage battery assemblies are employed to power the electric machines of electrified vehicles. The battery assemblies include battery arrays constructed of a plurality of battery cells. An enclosure assembly that often includes a tray and a cover houses the battery arrays. The enclosure assembly must be sealed and vented to prevent moisture from accumulating within the interior of the battery assembly. As governed by the Ideal Gas Law (PV=nRT), temperature fluctuations inside the battery assembly can create pressure differentials between the battery interior and surrounding atmosphere. These pressure differentials may create a vacuum that draws moisture and dust into the battery interior.